Time-dependent morphology evolution of solution-processed small molecule solar cells during solvent vapor annealing

Min J, Jiao X, Ata I, Osvet A, Ameri T, Baeuerle P, Ade H, Brabec C (2016)

Publication Language: English

Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2016

Journal

Advanced Energy Materials Wiley

Book Volume: 6

Article Number: 1502579

Journal Issue: 10

DOI: 10.1002/aenm.201502579

Abstract

Morphological modification using solvent vapor annealing (SVA) provides a simple and widely used fabrication option for improving the power conversion efficiencies of solution-processed bulk heterojunction (BHJ) small molecule solar cells. Previous reports on SVA have shown that this strategy influences the degree of donor/acceptor phase separation and also improves molecular donor ordering. A blend composed of a dithienopyrrole containing oligothiophene as donor (named UU07) and [6,6]-phenyl-C61-butyric acid methyl ester as acceptor is investigated with respect to SVA treatment to explore the dynamics of the BHJ evolution as a function of annealing time. A systematic study of the time dependence of morphology evolution clarifies the fundamental mechanisms behind SVA and builds the structure-property relation to the related device performance. The following two-stage mechanism is identified: Initially, as SVA time increases, donor crystallinity is improved, along with enhanced domain purity resulting in improved charge transport properties and reduced recombination losses. However, further extending SVA time results in domains that are too large and a few large donor crystallites, depleting donor component in the mixed domain. Moreover, the larger domain microstructure suffers from enhanced recombination and overall lower bulk mobility. This not only reveals the importance of precisely controlling SVA time on gaining morphological control, but also provides a path toward rational optimization of device performance. Time-dependent morphology evolution of solution-processed small molecule solar cells during solvent vapor annealing is systematically and methodically investigated. This not only reveals the importance of precisely controlling SVA time on gaining morphological control, but also provides a path toward the rational optimization of device performance.

Authors with CRIS profile

Jie Min Institute Materials for Electronics and Energy Technology (i-MEET) Andres Osvet Institute Materials for Electronics and Energy Technology (i-MEET) Tayebeh Ameri Institute Materials for Electronics and Energy Technology (i-MEET) Christoph Brabec Institute Materials for Electronics and Energy Technology (i-MEET)

Additional Organisation(s)

Exzellenz-Cluster Engineering of Advanced Materials

Involved external institutions

North Carolina State University US United States (USA) (US) Universität Ulm DE Germany (DE)

How to cite

APA:

Min, J., Jiao, X., Ata, I., Osvet, A., Ameri, T., Baeuerle, P.,... Brabec, C. (2016). Time-dependent morphology evolution of solution-processed small molecule solar cells during solvent vapor annealing. Advanced Energy Materials, 6(10). https://dx.doi.org/10.1002/aenm.201502579

MLA:

Min, Jie, et al. "Time-dependent morphology evolution of solution-processed small molecule solar cells during solvent vapor annealing." Advanced Energy Materials 6.10 (2016).

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